The present invention relates in general to improvements in a process and apparatus for exhausting fumes produced by arc welding.
Generally, during welding, there is an emission from molten welding flux, filler metal, base metal, etc. held at a high temperature, of micro-fine particles of iron, manganese, silicon and other harmful metal oxides (fumes in a narrow sense), as well as the emission of harmful gases such as nitrogen oxides gas, carbon monoxide gas or the like and other gases such as carbon dioxide gas (hereinafter these are generally called "weld fumes"). Therefore, to preserve the welder's health itis desirable to remove these weld fumes caused by the welding, and in the case of welding within a narrow compartment, the necessity of the removal of fumes is especially large.
Heretofore, as a means for exhausting weld fumes there are known apparatus in which a fume suction hood is provided in association with a welding protector which was held in the welder's hands during use and connected directly or via a connector to the latter and the hood was connected through a flexible tube to a bag filter provided separately, known apparatus in which a fume suction hood having various shapes designed so as to conform to configurations of bodies to be welded is disposed at a predetermined position such that the hood may surround a welding zone and the hood is connected to a fume processor (either of a fixed type or of a movable type) such as a bag filter or the like provided separately through one or more flexible tubes, and known apparatus modified from the second apparatus above in which the suction hood is mounted on an electrode holder or assembled integrally therewith.
However, the above-described respective weld fume exhausting means in the prior art have the following problems. The first apparatus has a problem in that since a suction hood is provided in association with a welding protector, a burden on a welder is increased; while the second apparatus can mitigate the increase of the burden on the welder because the suction hood is disposed so as to surround the welding zone, the second type of apparatus provided with a small suction hood and a fixed type fume processor has a problem in that each time the welding position is displaced, both the suction hood and the fume processing machine must be displaced; an apparatus provided with a large suction hood and a movable type fume processor has a problem in that a lot of labor is required for the reconnection of the flexible tubes resulting in a poor workability, and the apparatus is inevitably large-sized and hence cannot be used within a narrow compartment.
Furthermore, the third apparatus has a problem in that since the weight of the electrode holder is increased, the apparatus cannot be used in manual welding, and even if such a welding torch associated with a suction hood were to be mounted in a fully automatic welding machine, the apparatus is large-sized and thus could not be used within a narrow compartment.